This article seems to be a popular one, if the number of times it has been copied elsewhere is any indication. At one time there were more than ten websites sites that had appropriated it. Typical for the Internet. This article came out of two things. First, this is the same tool we had the students create at Motorcycle Mechanics Institute when I worked there as an instructor. Second, the incident described is real and happened at my then workplace, Eastside Performance Motorcycles, in Mesa, Arizona. The machine was a ZX11. I got the idea of rotating the crankshaft during the test from reading about Smokey Yunick, the fella who popularized the cylinder leakdown test--Google him. It worked. We replaced the bad cylinder sleeve. Those of you wishing to repost this article, why don't you just link to it instead? At least ask before taking it and putting it on your site. How do you think it feels to see your work claimed by others?